In the rechargeable battery industry a variety of different cathode materials have been investigated. LiCoO2 is the most common cathode material used today in commercial Li ion batteries, by virtue of its high working voltage and long cycle life. Although, LiCoO2 is considered the cathode material of choice, the high cost, toxicity and relatively low thermal stability are features where the material has serious limitations as a rechargeable battery cathode. These limitations have stimulated a number of researchers to investigate methods of treating the LiCoO2 to improve its thermal stability. However, the safety issue due to low thermal stability is still the critical limitation for LiCoO2 cathode materials, especially when the battery is used in high charging-discharging rate conditions. Therefore, LiCoO2 is not considered suitable as a cathode material in rechargeable batteries for transportation purposes and this has stimulated searches for alternative cathode material for use with electric vehicles and hybrid electric vehicles.
LiFePO4 has been investigated as a very attractive alternative cathode material in rechargeable batteries due to its high thermal stability which makes it suitable for high rate charge-discharge applications in transportation devices and power tools. Batteries using LiFePO4 as the cathode material have achieved market penetration in electric bicycles, scooters, wheel chairs and power tools.